Tipos de lapiaz generados en las cercanías de Zaragoza

Se han reconocido seis tipos de lapiaz sobre los materiales mesozoicos y terciarios que afloran dentro de la zona central de la Depresión del Ebro, en las cercanias de Zaragoza. De ellos, cuatro son formas conocidas: rillenkarren, solution pits (que sufren denudación), kluftkarren y hohlkarren (formas heredadas). Los otros dos micrornodelados son tipos no descritos anteriormente: lapiaz en escalones con crestas rectas y lapiaz alveolar, no habiéndose podido determinar su génesis. Sobre los depositos yesiferos se han encontrado rillenkarren y solution pits, que son funcionales actualmente

Superficies de erosión finiterciarias desarrolladas al S y SW de Zaragoza

Como consecuencia de la actividad tectónica que se registra en la Depresión del Ebro al final del Terciario superior, se producen ciclos de erosión-depósito que generan extensas superficies de erosión Dentro de nuestra hrea de trabajo hemos detectado dos de estas superficies, hallándose la más reciente encajada entre 40 y 50 m. con relación a la primera. La mas antigua se desarrolla sobre los materiales mesozoicos que se encuentran en la zona y enlaza con el techo de los depósitos neógenos. La segunda superficie afecta casi exclusivamente a estos Últimos materiales, siendo frecuente su asociación con costras carbonatadas. La edad de ambas está comprendida entre Plioceno medio y superior

Descripción y estudio preliminar del origen de la Depresión de Valdespartera (Zaragoza)

The central Ebro Basin was filled by evaporite (gypsum, principally) and carbonate deposits of a Neogene age. During the Quaternary age the fluvial activity caused the development of structural platforms and several nested levels of terraces and pediments. It is very frequent to find small depressions that, originally, had no connection with the drainage system. We study one of these, the Valdespartera depression, which is developed following the boundary between two different aterials, the gypsum Tertiary layers in the south and the terrace and pediment Quaternary deposits in the north. From the study of the morphological charactenstics, several factors which cooperate in its genesis can be pointed out: Structural factors (mainly he presence of fractures), the preferential erosion along the boundary between the Tertiary and Quaternary sediments, the dissolution of gypsum layers and piping processes. Wind could be an important transport agent of fine sediments, eventhough no proofs of its importance were found. The main process which generated this depression is gypsum dissolution as, the presence of alluvial dolines in the region, of small basins in the infilled valleys and a surface with an intermediate slope between the Tertiary and the bottom of the depression, indicate. Piping produces dragging of detrital materials in the conduits. These processes are favoured by fractures and the weakness of the contact between Tertiary and Quaternary materials

Monitoramento do clima no Pantanal.

Formato eletrônico

Boletim agrometeorológico: Fazenda Nhumirim - 1999.

Condições climáticas; Precipitação pluvial (mm); Temperatura do ar (oC); Evaporação do ar (mm); Umidade relativa do ar (%); Insolação (horas).bitstream/item/37738/1/DOC26.pd

Anomalous Roughening of Viscous Fluid Fronts in Spontaneous Imbibition

We report experiments on spontaneous imbibition of a viscous fluid by a model porous medium in the absence of gravity. The average position of the interface satisfies Washburn's law. Scaling of the interface fluctuations provides a dynamic exponent z \simeq 3, indicative of global dynamics driven by capillary forces. The complete set of exponents clearly shows that interfaces are not self-affine, exhibiting distinct local and global scaling, both for time (b=0.64\pm 0.02, b* =0.33 \pm 0.03) and space (a=1.94 \pm 0.20, a_loc=0.94 \pm 0.10). These values are compatible with an intrinsic anomalous scaling scenario.Comment: 4 pages, 5 figure